Slit mechanism for monochromator



April 5, 1955 K. P- GEORGE ET AL SLIT MECHANISM FOR MONOCHROMATOR Filed Oct. 8, 1949 5 Sheets-Sheet 1 f/v aw-0e: A z/vyo/v P GEORGE MCHAEL E. 5 TIC/(A/E'Y h 90 I M szil 9 Ana April 1955 K. P. GEORGE EI'AL 2,705,440

SLIT MECHANISM FOR MONOCHROMATOR Filed Oct. 8, 1949 3 Sheets-Sheet 2 April 5, 1955 K. P. GEORGE ETAL 2,705,440

SLIT MECHANISM FOR MONOCHROMATOR Filed Oct. 8, 1949 3 Sheets-Sheet 3 Br 7.46/2 A 770 ENE 15 //4 map,- M50155 r5? Jame/5 United States Patent sLrr MECHANISM FOR MONOCHROMATOR Kenyon P. George and Michael E. Stickney, Alhambra,

Calif., assignors to Beckman Instruments, Inc., a corporation of California Application October 8, 1949, Serial No. 120,348

19 Claims. (CI. 88-61) This invention relates to improvements in slit varying mechanisms and, more particularly, to improvements in slit varying mechanisms adapted for use with spectroscopic devices such as spectrophotometers.

In the past, variable slit mechanisms have utilized cams, wedges, or screws to actuate spring loaded jaws guided by dovetail or other types of ways to achieve the simultaneous and equal movement of bilateral jaws one with the other. Inherent in the use of such mechanical expedients have been the effects of hysteresis, lost motion and friction. For instance, the customary manner of mounting bilateral slit varying jaws is to secure them to guide plates which are mounted in ways and which are moved to cause the opening and closing of the jaws by a cam inserted between the ends of the guide plates. The frictional resistance of the guide plates to movement in the ways and the backlash encountered in the screw mechanism utilized to cause the rotation of the cam to cause the movement of the guide plates are disadvantages encountered generally in conventionally designed variable slit mechanisms. widths of 0.05 mm. are used, movements of geometric width in as small increments as 0.025 micron are necessary to change output energy in steps of 0.1%. It is obvious that hysteresis, drag and frictional losses militate against such proper functioning of the slit varying mechanism.

It is, therefore, a primary object of our invention to provide a slit varying mechanism which is free from the deleterious effects of hysteresis, backlash and frictional losses and which dispenses with the conventional mechanical elements customarily utilized in slit varying designs.

The aforementioned desirable object is attained by pivotally mounting the jaw members of the slit varying mechanism in such a manner that the reduction and expansion of the slits are accomplished by pivoting said jaw members toward and away from each other.

An additional object of our invention is the provision of pivotally moving carriage means for the jaw mem-v bers which carries the jaw members toward and away from each other to vary the widths of the slits.

A further object of our invention is the provision of jaw carriages of the aforementioned type in which resilient reed elements are utilized to accomplish the pivotal movement of said carriages and the consequent pivotal movement of the jaw members supported thereupon.

An additional object of our invention is the provision of pivotally movable and resilient carriage means for the jaw members which are characterized by resistance to both lateral and vertical dislocation, the jaw members being considered, for convenience, as moving toward and away from each other in a vertical plane.

One of the difficulties encountered in variable slit mechanisms manufactured in accordance with conventional designs and embodying conventional mechanical elements has been the fact that it is very difficult to move the two jaws of a bilateral slit mechanism so that the jaws will be moved simultaneously and equal distances.

Discrepancies in the initiation of movement and the minute differences in the distances traveled by each jaw of a pair of jaws are attributable to the above-mentioned factors of hysteresis, backlash, and frictional drag.

It is, therefore, an additional object of our invention to provide a variable slit mechanism in which the movable jaw means of the mechanism are interrelated with If, for example, slit 2,705,440 Patented Apr. 5, 1955 ice each other by a connecting means disposed therebetween in order that the movement of one jaw will be accompanied by the simultaneous and equivalent movement of its companion jaw.

A further object of our invention is the provision in a variable slit mechanism of connecting means of the aforementioned type which are resilient in nature and which are adapted to be deflected to draw the movable jaw means toward each other and to be released to permit the movable jaw means to move away from each other. An associated object of our invention is the provision of resilient-connecting means which are formed integrally with the movable jaw means and which can be installed in the mechanism together with the movable jaw means, thus eliminating much assembly necessary with prior art mechanisms.

A further object of our invention is the provision of actuating means for causing the movement of the movable jaw means toward and away from each other, said actuating means being connected to the connecting means which join the jaw means together in such a manner that the deflection 'of the connecting means by the actuating means causes the movement of the jaw means toward and away from each other and thus induces the jaw means to pivot upon their resilient carriage means.

Another of the difiiculties encountered in conventional slit mechanisms is the fact that the utilization of bilateral pairs of slits in which two jaw means must be moved simultaneously and for equal distances away from and toward each other necessitates the incorporation in the variable slit mechanisms of precision machined parts to govern and control such movement. In addition, dis tortion, mislocation and blurring of the spectral band due to the mislocation of one of the jaw means in reference to the other are frequently encountered in the use of such bilateral slit mechanisms.

A further object of ourinvention is the provision of a variable slit mechanism in which there is provided for each slit one movable jaw means and one fixed jaw means, the movable jaw means being carried toward and away from the fixed jaw means by the action of the actuating means upon theconnecting means to which the movable jaw means are secured or with which they are integrally formed.

An additional object of our invention is the provision of a variable slit mechanism providing a pair of variable slits, each of the slits being constituted by one movable jaw means and one fixed jaw means, connecting means between the movable jaw means causing the simultaneous and equal movement of the movable jaw means toward and away from the fixed jaw means when actuating means is caused to act upon the connecting means.

in a variable slit mechanism of a slit plate in which movable jaw means are formed integrally with each other. An associated object of our invention is the provision of integrally formed movable jaw means which are connected by means of a connecting means formed integrally therewith.

An additional object of our invention is the provision of a slit plate which may be formed by mass production methods, such as stamping, and which is formed of sheet spring stock so that integral and resilient connecting means joining the movable jaw means together may be provided.

An additional object of our invention is the provision of a variable slit mechanism which can be more easily and cheaply manufactured and assembled than conven-- tional variable mechanisms.

Other objects and advantages of our invention will be apparent from the following specification and the ac- 3 companying drawings, which are for the purpose of illustration only, and in which:

Fig. l is a perspective view showing one embodiment of a variable slit mechanism constructed in accordance with our invention;

Fig. 2 is a plan view of the slit plate which constitutes an important part of our invention;

Fig. 3 is a vertical sectional view taken on the broken line 33 of Fig. 1;

Fig. 4 is a plan view of the variable slit mechanism;

Fig. 5 is a fragmentary vertical sectional view taken on the broken line 55 of Fig. 3;

Fig. 6 is a perspective view of an alternative form of the slit plate of our invention;

Fig. 7 is a perspective view of an alternative embodiment of the slit varying mechanism; and,

Fig. 8 is a plan view of the variable slit mechanism shown in Fig. 7

Referring to the drawings, and particularly to Figs. 1 through 5 thereof, we show a variable slit mechanism 10 which is supported upon a mounting plate 11 which constitutes an end wall of the monochromator housing (not shown). The variable slit mechanism 10 includes actuating means 12 which is connected to a slit plate 13 mounted upon carriage means 14.

In considering the operation of the variable slit mechanism and its component elements, the directions of movement of the various portions of the mechanism will be described in reference to vertical mounting of the variable slit mechanism 10 upon the mounting plate 11 and the same terminology will be utilized in describing the movements of the parts in the various views although the orientation of the parts therein is not the same as the orientation of the parts as they are mounted upon the plate 11.

The actuating means 12 includes adjusting means 16 comprising a control knob 17 mounted exteriorly of the monochromator housing (not shown) and having associated therewith an indicia-bearing dial 18 adapted, in conjunction with a primary reference point upon the housing of the monochromator, to indicate the adjustment of the variable slit mechanism. Pressed into a longitudinal bore 19 formed in a bearing boss 20, which is integral with the mounting plate 11, is a sleeve 21 which has integrally formed thereupon a collar 22 impinging on the exterior of the monochromator housing and a hub portion 23 upon which the dial 18 associated with the control knob 17 is adapted to be rotated.

Formed in the sleeve 21 is an axial, threaded bore 25 in which is mounted a rotatable, micrometer screw 26 having a splined outermost end 27 upon which the control knob 17 is positioned and upon which it is maintained by means of a set screw 28. The rotation of the control knob in a clockwise direction, that is in the direction indicated by the arrow 29 in Fig. l of the drawings, will advance the micrometer screw 26, and conversely, counterclockwise rotation of the control knob 17 will cause the retraction of the micrometer screw 26.

Secured to the inner end of the micrometer screw 26, as by means of a set screw 33, is a collar 34 which prevents the retraction of the micrometer screw 26 within the threaded bore 25 beyond a predetermined point. Formed in the collar 34 is a recess 35 which provides a ball bearing seat 36.

Seated upon the ball bearing seat 36 of the collar 34 is a ball bearing 38 which is retained in one end of a push rod 39 which is adapted to transmit the movement of the micrometer screw 26 in' a manner which will be described in greater detail below. The push rod 39 is generally constituted by a web 40 which surrounds a rectangular aperture 41, the aperture 41 being provided to permit the passage of the light beams from and to the slit mechanism and to thus prevent the push rod 39 from interfering with the passage of said beams. Pressed into the other end of the push rod 39 is another ball bearing 43 which is seated in a ball bearing seat 44 formed upon the upper end of and integrally with a bellcrank 45. Formed upon one corner of the web 40 of the push rod 39 adjacent the bellcrank 45 is a stabilizing bar 46 which is received in an opening 47 formed in the bell-crank 45 and which, in conjunction with said opening, is adapted to prevent the rotation of the push rod 39 in the bearing seats 36 and 44 when the micrometer screw 26 is rotated. The stabilizing bar also serves,'to a certain extent, to prevent the shi g of the ball bearings 38 and 43 upon the seats 36 and 44. Secured to a bracket 49 mounted upon the bearmg boss 20 is the intermediate portion of a V-shaped tension spring 50, the opposite ends of which are received in apertures 51 formed in the upper end of the bellcrank 45. The spring 50, in addition to preventing the dislodgment of the ball bearings 38 and 43 from the bearing seats 36 and 44 respectively, also serves to place a sufiicient load on the micrometer screw 26 through the push rod 39 to prevent backlash in the micrometer screw.

The bellcrank 45 has two vertically spaced arms 53 and 54 connected by a bridge 55 in which are located the bearing seat 44 and the stabilizing bar opening 47. Formed integrally with the arms 53 and 54 and at right angles thereto are vertically spaced arms 56 and 57. Bellcrank mounting means 59 and 60 are located at junctures of the arms 53 and 56 and 54 and 57, respectively, and include, Fig. 3, generally triangular blocks 61 having caps 62 secured thereto by means of screws 63 and adapted to receive therebetween the ends of resilient reeds 64 formed of beryllium copper or similar sheet spring stock. The opposite ends of the resilient reeds 64 are secured between mounting bosses 65 formed integrally with the mounting plate 11 and caps 66 are fastened thereto by means of screws 67, or similar fasteners.

In this manner, the bellcrank 45 is adapted to pivot on the resilient reeds 64 when movement of the micrometer screw 26 is transmitted thereto through the push rod 39. The mounting of the bellcrank 45 upon the resilient reeds 64 eliminates the possibility that lost motion or frictional drag may occur during pivotal movement of the bellcrank and the manner of so mounting the bellcrank 45 is an important feature of our invention.

Considering the carriage means 14 of the variable slit mechanism, first carriage means 69 is secured to the mounting plate 11 by means of screws 71 and oppositely disposed to said first carriage means is a second carriage means 72 similarly secured by means of screws 73. Since the construction of the first and second carriage means 69 and 72 is identical in every respect, the first carriage means 69 is described and identical reference numerals are applied to the identical elements of the second carriage means. The first carriage means 69 includes vertically spaced side linkages 74 and 75, each of said side linkages including a base strip 76 between which strip and the mounting plate 11 are fastened the ends of resilient reed members 77 and 78, the upper ends of which are secured between a fastening strip 79 and opposite ends of a rectangular frame member 80 having horizontal side bars 81 and transverse bars 82 extending vertically between the side linkages 74 and 75. Rivets 83 fasten the upper ends of the reed members 77 and 78 between the fastening strip 79 and the side bars 81 of the frame member 80.

The first carriage means 69 and the second carriage means 72 are oppositely disposed to each other and, as indicated above, consist of vertically spaced side linkages 74 and which have incorporated therein resilient reed members 77 and 78 which pivotally support vertically positioned, rectangular frame members extending between the vertically spaced side linkages 74 and 75. Each of the side linkages 74 and 75 of the carriage means 69 and 72 thus comprises what is known as a three bar linkage and is thus adapted for pivotal movement in reference to the mounting plate 11. The utilization of the resilient reed members 77 and 78 as the crank links of the three bar linkages eliminates the possibility of hysteresis and backlash and the side linkages 74 and 75 thus support and carry the side bars 81 of the rectangular frame members 80 in a pivotal path with complete freedom of movement. Since the reed members 77 and 78 are resilient in nature, there is a tendency for the first and second carriage means 69 and 72 to be returned to a predetermined position, which tendency, however, is controlled by the movement of the micrometer screw 26 in a manner which will be described in greater detail below. The pivotal movement of the first and second carriage means 69 and 72 is a very important feature of our invention since it permits the carriage means to support the jaw means and to move them pivotally without the use of ways or other conventional mechanical expedients which have been hitherto utilized.

The slit plate 13, Fig. 2, is formed from a single piece 86 of sheet spring stock, such as beryllium copper, and includes a rectangular jaw plate 85 having a first jaw means 86 and a second jaw means 87 formed therein and connected with each other by means of integrally formed, resilient connecting means 88 and 89. The edges 90 and 91 of the first and second jaw means 86 and 87 are spaced a considerable distance from each other to leave a gap 92 therebetween. Formed integrally with the connecting members 88 and 89 and positioned intermediate the ends thereof are stabilizing and securing wings 93 and 94.

The aw plate 85 is secured to the transverse bars 82 of the rectangular frame members 80 of the first and second carriages 69 and 72, attaching strips 96 and rivets 97 serving to fixedly secure the first jaw means 86 to the first carriage means 69 and the second jaw means 87 to the second carriage means 72. The outer ends of the stabilizing wings 93 and 94 are respectively secured to mounting flanges 98 and 99 formed integrally with the mounting plate 11 by meansof screws 101, or similar fasteners. The attachment of the first and second jaw means 86 and 87 to the first and second carriage means 69 and 72 prevents the horizontal mislocation of the first and second jaw means while the attachment of the securing and stabilizing wings 93 and 94 to the mounting flanges 98 and 99 prevents the vertical mislocation of the slit plate 13 as a whole.

Disposed in the gap 92 between the edges 90 and 91 of the first and second jaw means 86 and 87, when said first and second jaw means 86 and 87 are mounted upon the first and second carriage means 69 and 72, is a fixed jaw means 103, Figs. 3 and 4, which includes a fixed jaw plate 104 secured to a mounting boss 105 formed integrally with the mounting plate 11 by means of a cap 106 and screws 107. The fixed jaw plate 104 has an edge portion 108 which is adapted to cooperate with the edge portion 90 of the first jaw means 86 to form a first variable slit 109 which is adapted to receive a light beam from a fixed slit 110 formed in the mounting plate 11. The fixed jaw plate 104 also provides an edge portion 112 oppositely disposed to the edge portion 108 and adapted, together with the edge portion 91 of the second jaw member 87, to form a second variable slit 113 adapted to transmit light to a fixed slit 114 formed in the mounting plate 11.

Securely mounted in the vertically spaced arms 56 and 57 of the bellcrank 45 are adjustablesockets 116 and 117 respectively which receive the lower ends of push rods 118 and 119, the upper ends of which are positioned in sockets 120 and 121 attached respectively to the connecting means 88 and 89 intermediate the ends thereof. The adjustable sockets 116 and 117 permit the adjustment of the connecting means 88 and 89 by adjusting the push rods 118 and 119. Thus, the movement of the vertically spaced arms 56 and 57 of the bellcrank 45 will cause the concomitant movement of the push rods 118 and 119.

Considering the operation of the variable slit mechanism in greater detail, when the control knob 17 is rotated in clockwise direction as indicated by the arrow 29 of Fig. l, the micrometer screw 26 is extended from the bore to shift the push rod 39 to the left and to cause the bellcrank to be pivoted upon the reed members 64 to move the ends of the vertically spaced bellcrank arms 56 and 57 in a direction away from the mounting plate 11 and to concomitantly shift the push rods 118 and 119 in the same direction. The movement of the push rods 118 and 119 in a direction away from the mounting plate 11 causes the simultaneous and outward bowing out of the resilient connecting means 88 and 89 and causes the concomitant and simultaneous movement of the first and second jaw means 86 and 87 toward the fixed jaw means 103 upon the first and second carriage means 69 and 72. The movement of the first and second jaw means 86 and 87 toward the fixed jaw means 103 brings the edge 90 of the first jaw means 86 toward the edge portion 108 of the fixed jaw plate 104 while the movement of the second jaw means 87 brings the edge portion 91 of the second jaw means 87 toward the edge portion 112 of the fixed jaw plate 104. Therefore, when the control knob 17 1S rotated in a clockwise direction, the resilient connecting means 88 and 89 are urged outwardly by the action of the push rod 39, the bellcrank 45 and the push rods 118 and 119 in a direction away from the mounting plate 11, thus bowing the connecting means 88 and 89 and drawing the first and second jaw means 86 and 87 toward each other to reduce the width of the first and second variable slits 109 and 113.

As the bowing outward of the resilient connecting means 88 and 89 takes place, the first and second carriage means 69 and 72 move toward each other, as permitted by the flexing of the resilient reed members 77 and 78 of the side linkages 74 and 75, to pivotally carry the first and second jaw means 86 and 87 toward the intermediate fixed jaw means 103. During the movement of the first and second jaw means 86 and 87 toward each other upon the first and second carriages 69 and 7 2, there is a slight lateral displacement of the edges 90 and 91 of said jaw means in reference to the intermediate fixed jaw member edges 108 and 112, but this slight movement is compensated for the focal length of the prism with which the variable slit mechanism is associated and, at any rate, is so slight as not to be an important factor in the operation of the variable slit mechanism.

When the control knob 17 is rotated in a counterclockwise direction, i. e., in a direction opposite to the direction of the arrow 29 of Fig. l, the micrometer screw 26 is retracted into the bore 25, permitting the push rod 39 to be shifted to the right by the action of the spring 50 connected to the upper end of the bellcrank 45 and by the action of the resilient connecting members 88 and 89 which move inwardly toward the mounting plate 11 and concomitantly carry the push rods 118 and 119 inwardly with them to accompany and, in some part, cause the inward movement of the ends of the vertically spaced arms 56 and 57 of the bellcrank 45. As the connecting means 88 and 89 move inwardly toward the mounting plate 11, the first and second jaw means 86 and 87 are shifted away from each other to carry the edge portions 90 and 91 thereof in a direction away from the edge portions 108 and 112 of the intermediate fixed jaw means 103. This movement of the first and second jaw means 86 and 87 is accompanied and facilitated by the pivoting of the first and second carriage means 69 and 72 in a direction away from each other. The movement of the first and second jaw means 86 and 87 toward and away from the intermediate fixed jaw means 103 is accomplished without the drag or backlash commonly encountered in conventional variable slit mechanisms and the response of the variable slit mechanism is thus immediate and accurate.

We thus provide by our invention a variable slit mechanism characterized by the absence of hysteresis and backlash and incorporating therein movable jaw means which are pivotally suspended upon carriage means incorporating resilient reed members adapted to permit the pivotal movement of the jaw means away from and toward each other. In addition, we provide a slit construction in which first and second variable slits having only one movable jaw means allotted to each slit are provided, a third fixed jaw means cooperating with the first and second jaw means to constitute the first and second variable slits. Another major feature of our invention is the provision of a slit plate which has formed integrally therein the first and second jaw means of the variable slit mechanism connected by integral connecting means, the movement of which is adapted to cause'the movement of the first and second jaw means toward and away from each other.

Shown in Fig. 6 of the drawings is an alternative embodiment of a slit plate 123, which is essentiallysimilar to t the slit plate 13 described in the previously disclosed embodiment but which is utilized to provide two variable slits 126 and 127, in a manner which will be described in greater detail below. Similar elements in the slit plate 123 are identified by reference numerals identical to those used in identifying the same elements in the slit plate 13. The slit plate 123 includes a jaw plate 85 which incorporates a first movable jaw means 86 and a second movable jaw means 87 joined to each other by resilient connecting means 88 and 89 formed integrally with said first and second movable jaw means. The slit plate 123 is adapted to be incorporated in a variable slit mechanism similar to the one above described and similar actuating means may be used to cause the movement of the first and second jaw means 86 and 87 toward and away from each other. The first and second jaw means 86 and 87 are mounted upon first and second carriage means 69 and 72 and a somewhat smaller gap 124 exists between the first and second 7 to form a first variable slit 126 and a second variable slit 127. By utilization of this construction, the interposition of an intermediate, fixed jaw means between the first and second movable jaw means 86 and 87 is not necessary and the edge portions 90 and 91 of the first and second movable jaw means, as divided by a separating member 125, constitute the first and second variable slits 126 and 127. It is obvious that by removal of the dividing member a single slit such as might be used in a spectroscope is provided.

An alternative embodiment of our invention is shown in Figs. 7 and 8 of the drawings, and constitutes a variable slit mechanism 130 which includes a first movable jaw means 131 adapted to cooperate with a fixed jaw means 132 to form a first variable slit 144, and a second movable jaw means 133 adapted to cooperate with a second fixed jaw means 134 to form a second variable slit 145. The first and second movable jaw means 131 and 133 are fixedly mounted upon a rigid connecting means 135 which has an elongated actuating arm portion 137 and mounting arms 138 for mounting the first movable jaw means 131 and mounting arms 139 for mounting the second movable jaw means 133.

The rigid connecting means 135 is pivotally supported upon resilient carriage means 140 exemplified as a pair of flexible reeds 141 formed from spring stock, such as beryllium copper, and each reed having an end mounted upon a mounting bracket 142 and an opposite end connected to a mounting arm 139 for the second movable jaw means 133. A tension spring 150 attached to the connecting means 135 holds the connecting means in such a position that the slits 144 and 145 are expanded. When a force is applied to the end of the actuating arm 137 of the connecting means 135 as indicated by the arrow 146 of Fig. 8, the carriage means 140, and especially the resilient reed members 141 thereof, permits the first and second movable jaw means 131 and 133 to be pivotally moved toward the fixed jaw means 132 and 134 against the tension of the spring 150.

When a force is applied to the end of the actuating portion 137 of the connecting means 135 in the direction of the arrow 146, the first and second movable jaw means 131 and 133 are carried toward the first and second fixed jaw means 132 and 134, since the force causes the deflection of the resilient reed members 141 to permit pivotal movement of the connecting means 135. When the force applied to the end of the actuating portion 137 of the connecting means 135 is released, the spring action of the reed members 141 and of the spring 150 is sufficient to return the first and second jaw means 131 and 133 toward their original positions and the first and second variable slits 144 and 145 are thus expanded. It is obvious from the above description of the operation and construction of the variable slit mechanism 130 that the movable jaw means 131 and 133 are pivoted toward each other and that the suspension of the movable jaw means upon the resilient carriage means 140 eliminates the backlash and drag commonly encountered in conventional variable slit mechanisms.

Although we have shown and described preferred embodiments of our invention, it is obvious that modifications, changes and alterations may be made in the specific details thereof and we, therefore, do not desire to be limited to such specific details but prefer rather to be afforded the full scope of the following claims.

We claim as our invention:

1. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including jaw members defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw members; carriage means for supporting saidjaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means connected to said resilient connecting means for moving said carriage means to shift said jaw members in one direction to reduce said slit and in theotherdirection to expand said slit.

2. In a variable slit mechanism, the combination of: a slit varying plate formed from a singlesheet of flat resilient material having jaw members with slit-defining edges extending toward each other in substantially the same plane and having elongated, reslient connecting means structurally integral with portions of said jaw members remote from said slit-defining edges; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means connected to said resilient connecting means for moving said carriage means to shift said jaw members in one direction to reduce said slit and in the other direction to expand said slit.

3. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient'material, said plate having a centrally located transverse opening providing an optical slit therein and a pair of elongated, longitudinally oriented openings communicating with said transverse opening and defining a pair of jaw members having slit-varying edges juxtaposed to said transverse opening, said longitudinally oriented openings also defining resilient connecting means structurally integral with said jaw members; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means connected to said resilient connecting means for moving said carriage means to shift said jaw members in one direction to reduce said slit and in the other direction to expand said slit.

4. In a variable slit mechanism, the combination of: a slit plate formed of a sheet of resilient material, said plate including jaw members defining a slit therebetween and movable in substantially the same plane to enlarge or restrict said slit, said plate having resilient connecting means structurally integral with and joining said jaw members and movable in a plane normal to the plane of said slit to cause the movement of said jaw members in their plane; carriage means for supporting'said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means connected to said resilient connecting means for moving said carriage means to shift said jaw members in their plane in one direction to reduce said slit and in the other direction to expand said slit.

5. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including jaw members defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw members, said resilient connecting means having laterally extending stabilizing means secured thereto; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon and having said stabilizing means fastened thereto to prevent mislocation of said connecting means; and actuating means connected to said resilient connecting means for moving said carriage means to shift said jaw members in one direction to reduce said slit and in the other direction to expand said slit.

6. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including jaw members defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw members, saidjaw members being movable in substantially the same plane toward or away from each other to restrict or enlarge said slit and said resilient connecting means being movable in a plane perpendicular to said plane of movement of said jaw members to cause the movement thereof; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means including actuating elements movable in the plane of movement of said connecting means and engageable therewith intermediate the ends thereof for causing the deflection of said connecting means and consequent movement of said jaw members.

7. In a variable slit mechanism, the combination of: a first movable jaw means; a second movable jaw means; three-bar linkage means mounting said first and second movable jaw means; a base having said three-bar linkage means mounted thereupon; first resilient connecting means connecting said first and second movable jaw means at one side of the ends thereof; second resilient connecting means connecting said first and second movable jaw means at the other side of the ends thereof; and actuating ineans operatively connected directly to said first and second resilient connecting means to shift said first and second movable jaw means toward or away from each other.

8. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including first and second movable jaw means defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw means; three-bar linkage means mounting said first and second movable jaw means; a base having said three-bar linkage means mounted thereupon; and operating means directly connected to said resilient connecting means for deflecting said connecting means to shift said first and second jaw means toward or away from each other.

9. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate having a centrally located transverse opening providing an optical slit therein and a pair of elongated, longitudinally oriented openings formed adjacent opposite edges of said plate and communicating with said transverse opening to form first and second movable jaw means in said plate and integral resilient connecting means connecting said jaw means for moving said jaw means toward or away from each other; three-bar linkage means mounting said first and second movable jaw means; a base having said three-bar linkage means mounted thereupon; and operating means directly connected to said resilient connecting means for deflecting said connecting means to shift said first and second jaw means toward or away from each other.

10. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate having an H-shaped opening formed therein, the transverse bar of which defines opposite slit-defining edges and the longitudinal bars of which are disposed adjacent the edges of said plate to define first and second movable jaw means having said slit-defining edges thereupon and elongated resilient connecting means structurally integral with said jaw means for connecting and moving said jaw means; three-bar linkage means mounting said first and second movable jaw means; a base having said three-bar linkage means mounted thereupon; and operating means directly connected to said resilient connecting means for deflecting said connecting means to shift said first and sec ond jaw means toward or away from each other.

11. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including jaw members defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw members; three-bar linkage means mounting said jaw members, said three-bar linkage means including resilient supporting means secured to opposite edges of said jaw members, said resilient means being defiectible to permit the movement of said aw members toward or away from each other; a base having said resilient supporting means secured thereto; and actuat ng means operatively connected to said resilient connecting means to cause the movement of said connecting means whereby said jaw members may be moved on said threebar linkage means toward or away from each other.

12. In a mechanism for varying slits, the combination of: a first movable jaw means; a second movable jaw means; first carriage means constituted by a three-bar linkage for pivotally moving said first movable aw means; second carriage means constituted by a three-bar linkage for pivotally moving said second movable aw means; a base supporting said linkages; resilient connecting means connecting said first and second movable jaw means; and

actuating means operatively connected to said resilient connecting means to shift said first and second movable jaw means on said carriage means toward or away from each other.

13. In a mechanism for varying slits, the combination of: a slit plate formed from a single sheet of resilient material, said plate including first and second movable jaw means defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw means; first carriage means constituted by a three-bar linkage for pivotallymoving said first movable jaw means; second carriage means constituted by a three-bar linkage for pivotally moving said second movable jaw means; a base supporting said linkages; and actuating means operatively connected to said resilient connecting means to shift said first and second movable jaw means on said carriage means toward or away from each other.

14. In a mechanism for varying slits, the combination of: a first movable jaw means; a second movable jaw means; first carriage means constituted by a three-bar linkage for pivotally moving said first movable jaw means; second carriage means constituted by a three-bar linkage for pivotally moving said second movable jaw means; a base supporting said linkages; resilient connecting means structurally integral with said jaw means, said connecting means being constituted by elongated strips disposed at the lateral edges of said jaw means; and an actuating mechamsm including actuating elements engageable with said strips intermediate their ends for moving said strips to cause the movement of said jaw means toward or away from each other.

l 5. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including jaw members defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw members; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means connected to said resilient connecting means, said actuating means including an elongated push rod disposed adjacent said plate engageable with a bellcrank disposed adjacent one end of said plate and actuating elements disposed between said bellcrank and said connecting means for deflecting said connecting means upon movement of said bellcrank to move said jaw members toward or away from each other.

16. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including firstand second movable jaw members having opposed edges at opposite sides of a centrally located opening in said plate and having resilient connecting means structurally integral with and joining said jaw members; fixed jaw means disposed in said opening in said plate and defining, in conjunction with said first and second movable jaw members, first and second variable slits; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means connected to said resilient connecting means for moving said carriage means to shift said jaw members in one direction to reduce said slits and in the other direction to expand said s its.

17. In a variable slit mechanism, the combination of: a slit plate formed from a sheet of resilient material, said plate including jaw members disposed and movable in substantially the same plane and defining a slit therebetween and having resilient connecting means structurally integral with and joining said jaw members, said connecting means being movable in a plane normal to the plane of movement of said jaw members; carriage means for supporting said jaw members; a base having said carriage means secured thereto for movement thereupon; and actuating means for moving said connecting means including a first elongated member disposed parallel to said plate and movable in a plane substantially parallel to the plane of movement of said jaw members and a second member disposed adjacent one end of said plate for transmitting movement of said first member to third members engag'eable with said connecting means intermediate their ends and movable in the same plane as said connecting means.

18. An optical slit varying plate formed from a single sheet of flat resilient material having jaw members with slit-defining edges extending toward each other in substantially the same plane and having elongated, resilient connecting means structurally integral with portions of said jaw members remote from said slit-defining edges whereby said connecting means may be bowed to move said slit-defining edges toward or away from each other, said connecting means having laterally extending, integral stabilizing portions for preventing displacement of said connecting means during movement thereof.

19. An optical slit varying plate formed from a single sheet of fiat resilient material, said plate having a centrally located transverse opening providing an optical slit therein and a pair of elongated longitudinally oriented openings communicating with said transverse opening and defining a pair of jaw members having slit-defining edges juxtaposed to said transverse opening, said longitudinally oriented openings also defining resilient connecting means structurally integral with said jaw .members at points remote from said edges whereby said connecting means may be moved to move said slit-defining edges toward or'away from each other, said connecting means having laterally extending integral stabilizing portions for preventing displacement of said connecting means during movement thereof. 1

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Knox Dec. 25, 1900 Garfield Nov. 18, 1902 Spinks Sept. 19, 1911 White Aug. 7, 1917 Brockett May 24, 1921 Le Tarte May 1, 1923 12 Wood May 22, 1923 Kwartin May '20, 1930 Kendall Mar. 8, 1932 Fassin Nov. 19, 1935 Sachtleben Dec. 24, 1940 Dimmick Dec. 2, 1941 Von Ardenne June 20, 1944 Gradisar Oct. 1, 1946 Fassin Oct. 8, 1949 

